The presence of collagen III and IV in experimental microsurgical anastomoses of arteries

PURPOSE: This study investigated the distribution of collagen III and IV in experimental microvascular anastomoses and correlated the findings with the quality of the healing process.

MATERIALS AND METHODS: A previously excised and reanastomosed section of the left common carotid artery of 21 female Wistar rats were explanted 4 weeks after surgery. Collagens III and IV were identified in perfusion-fixed specimens by immunohistochemistry.

RESULTS: The identification and distribution of collagens reflected the quality of each suturing procedure. A myointimal hyperplasia was present, extending into the vascular lumen, and was closely related to the ends of the vessel segments. The extent of myointimal hyperplasia was dependent on the length and the vitality of the vessel segments. The media was the weakest part of the tissue layers with regard to regenerative potential in the axial direction. The marked cuff of the adventitia around the anastomosis was rich in collagen III-positive vasa vasorum. Collagen IV was distributed in net-like patterns in the media. The distribution pattern in the media was not observed in anastomoses with incomplete approximation and necrotic segment ends. The collagen IV-positive subendothelial basal membrane was incomplete in the aneurysms because of partial necrosis.

CONCLUSIONS: The experimental findings support the need for atraumatic suturing in microvascular surgery. Immunohistochemical detection of collagens can be a valuable tool for studying the basic processes of wound healing and the integration of microvascular flaps into their recipient sites.